1 Field of the Invention
The present invention relates generally to packaging machines and, more particularly, to a vacuum packaging machine having an assembly for sealing the package after the inner volume of the package has been evacuated of air.
2. Discussion of the Prior Art
It is conventional to provide a vacuum packaging machine having an evacuation chamber within which a package is positioned during sealing. In such devices, a seal bar assembly is provided within the chamber and is movable between a storage position and a sealing position.
The seal bar assembly includes an elongated seal bar formed of an electrically insulative material, a sealing wire extending across the seal bar, a mechanism for moving the seal bar between the storage and sealing positions, and a separate electrical circuit for providing electricity to the sealing wire. The electrical circuit includes wires extending from the ends of the sealing wire out of the chamber to a power source.
Because the wires extending from the ends of the sealing wire must bend twice during each sealing cycle of the machine, fatigue failure of the wire material limits the useful life of the seal bar assembly Further, by isolating the wires from the moving mechanism and leading them from the chamber without providing a point of detachment for the wires, repair or replacement of the seal bar assembly is complicated since removal of the seal bar is difficult.